Method of improving ferrous metals and products thereof



Patented May 14, 1929.

UNITED STATES PATENT' OFFICE.

, mums'r 8. IIBHEB, OI SAIi'I LAKE CITY, UTAH, ASSIGNOB TO UTAH METALS FLUX.

' CODA, F SALT LAKE CITY, UTAH, A CORPORATION 01 UTAH.

METHOD 0! IMPROVING FERROUS METALS AND PRODUCTS THEREOF.

No Drawing. Original application filed J'une25, 1924, Serial No. 722,409. Divided and this application filed August 20, 1926. Serial No. 130,561.

This invention relates to methods of improving ferrous metals, and particularly to treatments in which substances are either added for this purpose to a fused bath of the 5 metal or applied to the solid metal while at a substantially elevated temperature.

More particularly my invention relates to the improving of ferrous metals by the action of certain naturally occurring deposits which have been found to not only purify the metals but positively to impart to the same desirable mechanical characteristics.

I have found that there are certain deposits of shale which possess the property of effecting the improvements mentioned. One such deposit is in the northern'central portion of Emery County, Utah, south of the Price River and Desert Lake. This shale, which is to be distinguished from the blue or bluegray variety found in the same vicinity, 1s

a highly laminated carbonaceous or bituminous shale varying in color from dark brown or almost black through brown to brick-red, with frequently a yellowish tint on the surfaces of the laminae.

The shale is susceptible of quite varied use in metallurgical operations, but I shall con-.

fine the present description mainly to certain of the uses which have been thoroughly tried out and the products of which have proved thoroughly satisfactory.

If from 1 to 10 percent by weight of this shale is cooked with scrap iron, even poor grades of cast iron, there results from the melt a product which is clean, solid, and malleable and the tensile strength of which is enormously increased. Castings made directly from the bath are clean, more free from fins than cast iron castings, and readily workable, and may be machined at much higher speed than customarily can be employed in working cast iron. Castings of this product may be made much lighter than heretofore on account of the strength of the product and its highly dense and fibrous nature.

Iron treated according to my method may be welded without the use of a flux, and in this manner distinguishes greatly from cast iron. Using sticks or the like made of the treated iron as welding rods enables cast iron pieces to be welded together without the use of other fluxing media. In either case the welds are not hardened and are as machinable as the original pieces. On many tests, the welds proved stronger than the original pieces.

I find in general than an addition of from 1 to about 6 percent of the shale to the molten bath softens and toughens the product, while higher roportions of the shale have a hardemnge ect.

Another useful application 'of my inventlon 1s 1n cupola practice. I have found that the addition of from 1 to 15 ercent by weight ofthe shale to the charge 0 iron or iron-contaming metals and coke or other fuel in the cupola furnace not only reduces the improvements and characteristics referred to, in the batch to which the shale has been directly added, but that the effect of the flux or agent permeates the superineumbent charges to an appreciable extent; so much so that the foundrymen will recognize the product at once on casting and machining. The vapors evolved in the heating process there- 75 fore carry to some extent the active substance of the shale, although of course the effect is most noticeable in the molten portion of the 'charge to which the flux has been directly added. The oupola treatment softens the texture, fiber or grain of the metal, toughens the same and strengthens the casting, producing in effect a casting similar to a wrought or malleable. iron; at the same time practically eliminating and freeing the same from any oxygen, nitrogen or other deleterious elements, thus producing a solid, sound casting free from blow-holes or other imperfections.

Relative to the extent to which the treatment described improves the metal, I may state that the average transverse strength of good cast iron is in the neighborhood of from 2500 to 2900 pounds, whereas castings of iron made in accordance herewith test from 3600 to .4500 pounds per square inch transverse strength.

The improvements noted as to treated cast iron are equally obtained in the treatment of steel.

Molten cast iron when contacted with from four to six percent of the shale as heretofore described when used in welding cast iron to cast iron produces, without the use of any other flux, a joint which is exceptionally strong and easily machined and which is 1 5 practically free from pittings or gas holes.

I do not know at the present-time exactly what the effect is due to, but I believe that it results from a complex reaction between certain of the constituents of the shale and of the metals, and ossibly the isolation of some unknown material whlch acts, perhaps catalytically, as" homogenize and condense the metal in its presence.

An average analysis of this shale shows its composition to be about as follows:

Silica 45% Iron oxide 10% Aluminum oxide 12% Calcium oxide 2.5% Magnesium oxide s 1% Sulphur .087% Phos' horus 068% All!!! iesa. Titanium Trace Vanadium .013 5% Uranium Trace .37 1/0 Carbon 10.24% It is to be understood that the titanium, vanadium and uranium components of the said shale occur not as free elements but in the form of compounds,probably as 0xides, carbides or sulfides,thereof.

It is possible that other samples of this shale capable of effecting the results mentioned Wlll vary considerably in proportions in the majority of ingredients mentioned, but the above is an average analysis of the particular shale in the region described.

The various analyses which have been made show losses on ignition varying from 15 to 31 percent. It is possible that some ofthe substances thus lost on ignition play an important part in the mechanism of the reactlon which occurs. This theory is borne out in part by the fact that the upper layers of the charge in a cupola or similar furnace undergo improvement which is quite noticeable, although the shale itself is added and confined to the lowermost portion of the char e.

0 .course the slag which is formed upon melting is removed before or upon pouring.

Metals, particularly impure scrap iron, when treated as described, lose weight to some extent, probably due to the scavenging action of the shale.

It will be. understood where I have stated in theappended claims that the shale is introduced into the molten bath, I also contemplate the introduction of the shale into the crucible,

furnace or other apparatus either before, alon with or subsequent to the introduction of t e metal or metals.

This. application'is a*division of m copending application Serial No. 722,409, filed June 25,1924.

I claim:

1. Method of improving ferrous metals which comprises contacting the same in molten state with a composition substantially identical with the carbonaceous shale found in the northern central portion of Emery County, Utah, south of Price'River and Desert Lake.

2. Method of improving iron which comprises contacting the same in molten state with a composition substantially identical with the carbonaceous shale found in the northern central POIlJlOIl'Of Emery County,

Utah, south of Price River and Desert Lake.

3. Method of producin malleable cast iron having physical characteristics of wrought iron which comprises melting cast iron and introducing thereinto about from 1 to 15% by weight of a composition substantially 1 identical with the carbonaceous shale found in the northern central ortion of Emery County, Utah, south 0 Price River and Desert Lake, and casting the metal into shape in suitable molds.

4. Method of improving steel which comprises contacting the samein molten state with a composition substantially identical with the carbonaceous shale found in the northern central portion of Emery County, Utah, south of Price River and Desert Lake.

5. Malleable cast iron possessing the physical characteristics of wrought iron, produced by subjecting molten cast iron to the infiuen ce of a heated composition substantially identical with the carbonaceous shale found in the northern central portion of Emery County, Utah, south of Price River and Desert Lake.

6. Method of producing iron for welding rods which comprises establishing a molten bath of cast iron and introducing thereinto from 4 to 6 percent by weight of a composition substantially identical with the carbonaceous shale found in the northern central portion of Emery County, Utah, south of Price River and Desert Lake, and forming the metal into rods.

In testimony whereof, I afiix my signature ERNEST S. FISHER. 

